For each organization, we identify the 10 prospects with the highest ceilings, with consideration given to the likelihood of reaching those ceilings.

To qualify as a prospect, a position player cannot exceed 130 big league at-bats, while a pitcher cannot exceed 50 innings or 30 relief appearances. These thresholds mirror major league rookie qualifications, albeit without regard for major league service time.

Track Record: As a tall, thick-bodied righthander, Whitley was considered one of the better prep prospects in the 2016 draft class. But during his senior season, he wowed scouts after he melted away 20-30 pounds, turning himself into a more athletic pitcher with still-excellent stuff. By the end of his senior year, he was touching 97 mph and breaking off 90 mph sliders. In his first full pro season in 2017, Whitley dominated three levels and became just the fifth high school first-round pick to pitch at Double-A in his first full season this century. The previous four were Chad Billingsley, Zack Greinke, Clayton Kershaw and Dylan Bundy.

Scouting Report: Few young pitchers are as advanced as Whitley, and few can match the quality of his stuff. He entered 2017 with four quality pitches and left it with five. All his pitches are at least average and a trio are already plus. Pitching with an over-the-top arm slot emphasizes the downhill plane on his fastball, and Whitley can blow hitters away at 92-97 mph. He actually is even more comfortable toying with batters with his varied assortment of offspeed pitches, and he commands his breaking balls better than his fastball at this point in his career. His plus 84-87 mph slider has modest depth but strong tilt as it dances away from his opponent’s bat head as it nears the plate. His 78-82 mph curveball is also plus with a big 12-to-6 break. At times his changeup will also show otherworldly movement, when it dives down and away from the barrel of lefthanded batters. And in 2017 he refined a 90-92 mph cutter that some scouts throw a plus grade on. With so many pitches, Whitley can stick one or two in his back pocket early in the game, then break them out the second time through the order. One of the few criticisms raised is that he’s a slow worker.

The Future: Scouts are understandably reticent to project almost any pitcher as a future No. 1 starter. But Whitley has a chance to be an ace with dominant stuff and advanced feel and control. It would surprise no one to see a 20-year-old Whitley make his major league debut later in 2018. He doesn’t require much projection. He has not yet thrown even 100 innings in a season, so the Astros will likely be conservative with his workload in 2018.

Track Record: The BA High School Player of the Year in 2015, Tucker broke his brother Preston’s school home run record. Early in his pro career, he impressed with an advanced approach and hit tool. He showed a significant power increase in 2017, when he sacrificed contact to hit 25 home runs and reach Double-A Corpus Christi.

Scouting Report: Tucker’s swing has never been picture perfect. He begins his swing with the bat laid back over his shoulder, leading to a little bit of a sweepy beginning. But it’s hard to argue with the results. His excellent hand-eye coordination leads to ton of contact, and as he has gotten stronger he’s turned doubles into home runs. Tucker isn’t a true center fielder, but he has a chance to be fringe-average there while being above-average in the corners with an average arm that works in either spot. He’s an average runner who has shown a knack for stealing bases.

The Future: Tucker’s even-keeled approach turns off some scouts, who describe him as low-energy. He has a half-season of Double-A experience under his belt before his 21st birthday so he may need a little more Double-A time, but a big league arrival by age 22 is a likelihood.

Track Record: The Dodgers and Astros battled to sign Alvarez when he left Cuba. The Dodgers won that battle, signing Alvarez on the last day of the 2015 signing period for $2 million. The Astros traded for Alvarez in August 2016, before he ever played a game for the Dodgers.

Scouting Report: Alvarez earned a spot in the Futures Game in 2017, his first full season. A wrist injury sapped his power in the second half, but when healthy Alvarez showed some of the best power in the organization. He produces high exit velocities and has 25-plus home run potential. His swing is not really geared for power, but the ball carries thanks to leverage and bat speed. Alvarez uses a whole-field approach, and hit more home runs to the opposite field than his pull side. He has a big strike zone, but his ability to recognize breaking balls and lay off pitches out of the zone helps him cover the plate. Alvarez is an above-average runner underway and is a better left fielder than first baseman. His fringe-average arm is his worst attribute.

The Future: Alvarez needs to continue to refine his game, but he has an exceptionally high ceiling as a pure hitter with a chance for plus power. He will be ready for Double-A Corpus Christi in 2018 with a strong spring.

Track Record: Much like Lance McCullers Jr., Bukauskas is a short, hard-throwing righthander with an exceptional breaking ball whom some scouts see as a reliever, but whom the Astros believe can start. Bukauskas went 9-1, 2.53 with 116 strikeouts in 92.2 innings as a North Carolina junior.

Scouting Report: Bukauskas had the best slider in the 2017 draft class. It’s a 70 pitch on the 20-80 scouting scale. He relied on it too often in college—in some outings he threw more sliders than fastballs—but it’s a pitch that requires no projection because it’s already hard (85-87 mph) with sharp, late bite and comes out of his hand looking like his 91-95 mph fastball. Bukauskas can touch 96 mph, but his velocity usually dips into the lower registers of his range as the game wears on. He has average command and control of his fastball but plus command of his slider, and he often succeeds with a largely two-pitch approach. His 84-86 mph changeup flashes average, and its development will be one of the keys to him remaining in the rotation.

The Future: Bukauskas has a high floor because his fall-back option is potential closer, but he also has a chance to be a Sonny Gray-esque starter.

Track Record: Nova was expected to be the centerpiece of the Marlins’ 2016 international signing class before a positive steroid test pushed Miami away. The Astros then signed him for $1.5 million. His bonus was then reduced further to $1.2 million after an issue with his elbow. Nova has passed every drug test since then, while staying healthy and showing unchanged athleticism and twitchiness.

Scouting Report: Nova’s earliest big league ETA is some time in the 2020s, but there are few Astros prospects with more potential. He has a chance to be an impact bat who can stick at a middle-infield position. He’s athletic with above-average bat speed, plus speed and a plus arm. Nova shows surprising power for a speedy teenager. Like a typical 17-year-old, he has to make strides in pitch recognition, but with his bat speed and bat-to-ball skills, he has a chance to be an above-average hitter with average power. Defensively, Nova’s hands work well, he has the twitchiness for a quick first step and the arm to make plays in the hole.

The Future: Nova is ready to head to play for a U.S. affiliate. The teenager faces plenty of work ahead, but he has a chance to be an impact everyday shortstop.

Track Record: Solis was considered one of the better players in the Astros’ 2016 international class and landed a $450,000 bonus that reflected it. The Astros liked how his arm worked and thought he had room to fill out. Since then, he has exceeded expectations.

Scouting Report: Solis has put in a lot of work, improved his body and has seen his stuff jump up as well. When the Astros signed him, he could touch 91 mph. Just a year later, he sat 90-94 mph and touched 96 with a fastball that has late life. Once Solis made his pro debut, it was hard to hold him back. He sped from the Dominican Summer League to the Rookie-level Gulf Coast League to the Rookie-level Appalachian League in the span of two months in 2017. He misses bats and shows advanced control for a teenager. Solis has a hard, slurvy 76-78 mph slider that shows plenty of promise. He also quickly picked up an 83-85 mph changeup that shows some late tumble. The Astros are also encouraged by his intelligence and aptitude.

The Future: Solis could make it to low Class A Quad Cities in 2018, and with his feel he may continue to move quickly.

Track Record: When Perez throws strikes, he dominates. He wasn’t particularly dominant in 2017 because he walked 6.5 batters per nine innings in a season spent primarily at high Class A Buies Creek.

Scouting Report: Perez is a fast mover who has gone from the complex leagues to high Class A in two years, but his control problems have forced him to develop survival skills. There’s nothing particularly ugly or problematic about his delivery, but he has trouble staying in sync. His wildness has few apparent patterns—he will spike a ball in the ground after 55 feet and the next ball will be up and out of the zone—but Perez’s arm is special. He sits 92-97 mph and has touched 99. When he keeps his fastball around the strike zone, he sets up his plus low-80s split-changeup that leaves hitters flailing. He can locate a potentially average slider at times but it can sometimes blend with his 78-80 mph curveball.

The Future: Perez’s control troubles lead to speculation that he’s destined for the bullpen, where he would likely touch 100 mph, but he has a good frame and his delivery isn’t awful, so there’s no reason to give up on starting.

Track Record: The Astros signed Alcala as a late-blooming 18-year-old. He sat 90-92 at that point, but since then his velocity has improved by leaps and bounds.

Scouting Report: Alcala’s fastball ranges from 93-99 mph. He generally sits in the mid-90s and has touched 100-102. His slider and changeup are both much less refined, but the quality of his fastball allows them to play up. His slurvy slider will flash average mainly because it’s 88-90 mph and has some modest late break. His below-average changeup doesn’t move much, but when he maintains arm speed and throws it with conviction, hitters have a hard time gearing down from 100 to 87-88. If Alcala could refine one of the two offspeed pitches into a two-strike weapon, he’d shorten his innings significantly. Alcala’s control needs to improve, but he showed improvement with that in 2017, especially when working out of the stretch.

The Future: Alcala is another flame-thrower in the Jorge Guzman/Albert Abreu mold. It’s easy to see Alacala eventually ending up in the bullpen, but with physicality, athleticism and a delivery with no glaring issues, he’ll keep trying to stick as a starter.

Track Record: Paulino only added to concerns about his durability in 2017. He missed the start of the season with a sore elbow and returned in May, but just a month later he was suspended for 80 games after testing positive for a steroid.

Scouting Report: Paulino came off the suspension on the final day of the season, but was immediately put on the 60-day disabled list because of surgery to remove bone chips in his pitching elbow. Paulino will be 24 when the 2018 season begins, but he’s yet to prove he can hold up over a full season. Between Tommy John surgery and suspensions, he’s yet to throw 100 innings in a season. When he’s healthy, Paulino has a 91-94 mph fastball and a devastating, 82-84 mph plus curveball. The fastball wasn’t as hard in 2017 as it’s been in the past, but the curve retains its sharp 12-to-6 break and Paulino has the feel to manipulate it depending on the situation. He can make it bigger and slower or harder and sharper. His changeup also flashes plus.

The Future: Paulino still has the makings of a mid-rotation starter, but he is now one positive test away from a full-season ban.

Track Record: The Astros’ depth at first and third base meant that Davis faced a tough-to-swallow assignment in 2017. Coming off of a productive full season at Double-A Corpus Christi and a strong spring training, he was sent back to the Hooks because Houston had Alex Bregman and Yuli Gurriel set in the majors and Colin Moran and A.J. Reed above him in Triple-A. To Davis’ credit, he didn’t pout and was a little more productive in a second stay with the Hooks. He eventually made it to Triple-A and made his big league debut. He even got to show off his big arm, throwing 92-93 mph fastballs in mop-up relief work.

Scouting Report: Davis has some of the best raw power in the organization and one of the strongest arms. It will always come with a significant number of strikeouts and he’s unlikely to hit better than .230-.240 albeit with decent on-base percentages because he draws some walks. While many Astros have embraced hitting more fly balls, Davis’ swing leads to a lot of screaming ground balls. If he could get the ball into the air more he could hit 30+ home runs.

The Future: Davis is a fringe-average defender at third and is the same at first with limited range but good hands. He’s also tried left field, where his arm is an asset, but his below-average speed is a detriment. Davis is an injury fill-in for the Astros for now, which may make him a trade asset eventually.